Mitogenic activity for fibroblasts was recognized in brain extracts over 40 years ago by Trowell et al., (1939) J. Exp. Biol., 16, 60-70 and Hoffman, (1940) Growth, 4, 361-376. The first claim of purification to homogeneity of a brain-derived growth factor was made by Gospodarowicz, et al., (1976) Third International Symposium on Growth Hormone and Related Peptides, Sept. 17-20 (1975) Milan, Italy, Excerpta Medica/Elsevier, New York, pp. 141-165 and (1978) J. Biol. Chem. 253, 3736-3743., who described a variety of activities and target cells of the mitogen, Gospodarowicz, et al., (1975) in Adv. in Metabolic Disorders, eds., Luft, R. & Hall, K. (Academic Press, New York) Vol. 8, 301-335. After an approximately 1000-fold purification from a crude bovine brain homogenate the active protein, fibroblast growtn factor (FGF), was reported to be a family of 3 proteolytic fragments of myelin basic protein, Westall, et al., (1978) Proc. Natl. Acad. Sci. USA 75, 4675-4678, a constituent of the myelin sheath surrounding many brain and peripheral neurons.
The identification of the mitogens as degradation products of myelin basic protein subsequently was disputed, Thomas, et al., (1980) J. Biol Chem. 255, 5517-5520 and Lemmon, et al., (1982) J. Cell Biol 95, 162-169, and the fragments of myelin basic protein were ultimately confirmed to be the major protein species in these preparations but were not the active mitogens.
Now, with this invention, there is provided a process for the 35,000-fold purification of acidic brain fibroblast growth factor and a characterization of the protein.
Also provided by this invention are pharmaceutical compositions comprising the novel growth factor as active ingredient, and a method of treating wounds of mammals including humans by the administration of the novel growth factor to patients in need of such treatment.